Apparatus for producing fibrous elements



Dec. 9,- 1958 J, CLARK 2,863,476

APPARATUS FOR PRODUCING FIBROUS ELEMENTS Filed Oct. 2, 1953 INVENTOR.

ATTORNEYS.

States Patent Ofifice P atented Dec. 9, 1958 APPARATUS FOR PRODUCINGFIBROUS ELEMENTS James dA. Clark, Longview, Wash., assignor toChangewood Corporation, Chicago, 111., a corporation of Illi- Thisinvention relates to apparatus for the production of wooden wafersadapted to be used in the manufacture of boards and panels by molding,preferably under heat and pressure, and its relates more particularly toimprovement in apparatus for the manufacture of wafers of the typedescribed from blocks of wood, scrap wood or other cellulosiccomposites, having at least two edges tapered, as by the methoddescribed in my copending application Ser. No. 78,692, filed on February28, 1949, now Patent No. 2,655,189 of which this application in acontinuationin-part. In addition, the apparatus forming the subjectmatter of this invention can be used to produce fibrous elements of thetype described in my copending application Ser. No. 344,089, filed onMarch 23, 1953 now Patent No. 2,773,789, issued December 11, 1956, whichis a continuation-in-part of abandoned application Ser. No. 192,284,filed on October 26, 1950, with the improvement in that the wafers orelements can be formed with all four edges tapered.

As explained in the aforementioned application Ser. No. 192,284, whenmolded under heat and pressure in admixture with a small amount ofadditional resinous binder, the wafers having tapered edges transverselyof the grain of the wood produce vboards having higher strength andbetter appearance than boards molded of wooden elements of the typeswhich had theretofore been produced. However, if the wooden elements orwafers are relatively thick, such as greater than 0.015 inch, and in theevent that the wafers are formed of hard wood or wood which containshard wood and semi-annular rings, as in most southern pines, then it isadvantageous to make use of wafers which are tapered also along theedges parallel to the grain of the wood to the end that reduced pressurecan be used to integrate the elements into a product of lesser weightper unit thickness but wherein, because of the taper all around theedges of the wafers, the wafers are still able to merge into the facesof tapering elements to produce a stronger board and a smoother andbetter appearing surface.

Briefly described, the apparatus used in the preparation of wafers inaccordance with the aforementioned application Ser. No. 78,692, consistsof a horizontal table which rotates continually about a vertical axisand which carries on its surface one or more cutting cylinders thatrotate about a horizontal axis independently of and at the same time asthe table and Which also carries one or more radially mounted scoringdiscs which extend forwardly from the surface of the table. The hopperscontaining the wooden blocks for cutting into wafers are radiallyarranged above the horizontal table whereby the ends of the blocksadjacent the surface of the tables are engaged by the cutting edges ofthe knives and by the scoring elements. the elements cannot be formedwith tapered side edges unless the vertically disposed scoring discs arereplaced with fixed knives mounted at a transverse angle so as to scorethe wood in a manner to define and form the taper With an arrangement ofthe type described,

2 for the side edges when the wafers are severed from the block.

Substitution of fixed knives angularly arranged is objectionable becauseof the disturbing efiect which they will have. on the wooden blocks inthe hopper since the blocks will have a tendency to be displaced by thefixed scoring members and will tend to cause lateral shifting movementof the blocks within the hoppers since an arcuate rather than a straightseries of parallel scores of cuts are made with the horizontalwaferizing machine. As a consequence, it is preferred to achieve theproduction of wafers having tapered side edges by scalloping orstaggering the main cutter knives, such as described in theaforementioned application Ser. No. 192,284. Even then the elements cutfrom the extremities of the pieces of wood, that is the portion adjacentthe leading and trailing edges of the hopper nearest the center of thedisc, will be severed at an appreciable angle, say overlS", to eitherdirection of the grain or in the direction at right angles tothe grainby reason of the arcuate path of the cutting knives. Consequently,unless the disc is made of unduly large diameter, such wafers have beenfound to be unduly weak and less desirable for use in the molding ofcomposite boards and panels.

In the apparatus described in applications Ser. No. 192,284 and Ser. No.344,089, which is used for the manufacture of waters having taperededges, no means are provided for limiting the lengths of the elements inthe direction of cut except by way of limiting the thickness of thewooden slabs fed into the machine for waferizing. In the event that theelements are to be produced from scrap logs and thick pieces of woodWaste, it becomes necessary to cut the wood into slabs of the thicknesscorresponding to the maximum length desired in the wafers, which isgenerally less than 5 inches and generally from 0.5 to 2 inches. Thispreliminary step accounts for waste of equipment, labor and woodenmaterial. In addition, means are not available in equipment of the typedescribed for providing the desired taper at the edges of the elementsformed at the beginning and at the end of each.

It is an object of this invention to produce a new and improvedapparatus for making fibrous elements or wafers with tapered edges andit is a related object to produce apparatus of the type described whichyields wafers independent of the shape or thickness of the: wooden slabsfed thereto for waferizing.

Another object is to provide a waferizer of the type described forcutting such elements from wood, either parallel to or at right anglesto the grain of the wood.

A further object is to provide apparatus of the type described whichproduces wafers having tapers on both its side and front and back edges.

A still further object is to provide a waferizer of the type describedwhich is simple in construction and easy in operation for use in theconversion of wood waste and wooden blocks in an economical andeificient manner into wooden elements which can be used in themanufacture of rigid boards, panels and the like molded prod ucts havinghigh strength and excellent appearance and without the addition ofsubstantial amounts of additional binder.

These and other objects and advantages of this invention willhereinafter appear and for purposes of illustration, but not oflimitation, an embodiment of the invention is shown in the accompanyingdrawing in which:

Figure 1 is a sectional elevational view of a waferizing machineembodying features of this invention;

Figure 2 is a fragmentary view in sectional elevation taken alongtheline 2-2 of Figure 1 illustrating the construction and operation of acutting head of the type illustrated in the machineof Figure 1;

Figure 3 is a partial sectional view taken through a portion of Figure 1and illustrating a scoring means;

Figure 4 is a diagram which illustrates the improvement of a cutterblade to sever a wafer from the wooden block with apparatus embodyingfeatures of this invention;

Figure 5 is a sectional elevational view illustrating a modification ina waferizing machine embodying features of this invention, and

Figure 6 is a plan view showing a modified form of cutting blade whichmay be employed in the practice of this invention.

Briefly described, invention resides in an apparatus comprising a pairof disc plates mounted on a shaft to form a large spool which supports aplurality of individually driven cylindrical cutting heads on theperiphery thereof in position to engage the faces of pieces of wood inthe form of wooden blocks or the like fed in the direction towards thecutting elements. The thickness of the elements cut depend on the rateof feed and the spaced relation of the cutting elements in thecylindrical cutting head as well as the rotational speed of the cuttingheads. The width of the elements, as measured by the distanceperpendicular of the plane of Figure 1, is controlled chiefly by thespacing of the scoring knives, as shown in Figure 3, or by the length ofthe scallops in the edges of the main cutter knives, or by theindividual lengths of the cutter knives in the event that the knives arestaggered. The length of the elements produced will be determined by thediameter of the cutter beads, by the thickness of the elements cut andby the relative peripheral speed of the spool carrying the cutter headsand the peripheral speeds of the revolving heads as discussed in theparent application Ser. No. 78,692.

Referring now to the drawing for a more specific description of awaferizer embodying features of this invention, wooden slabs such as thelogs it), scrap wood or the like are advanced forwardly at a constantspeed for cutting on a conveyor, such as an endless feed chain 11operating about sprockets 12 driven by a motor 13. A variable speeddrive 14 is interposed and is operatively connected to the drivensprocket 12 and to the driving motor 13 by chains 15 and 16 to provideadjustment for speed to vary the thickness of the wafers cut from thepieces of wood. Lugs or teeth 17 are provided on the endless feed chain11 for positive engagement to advance the pieces of wood 10 on thesurface thereof into feeding relation with the cutting knives, whichwill hereinafter be described. The upper surfaces of the pieces of woodare engaged When advanced to the cutting areas by one or more hold-downdogs l3, l9 and 20 of variable length and which are mounted for pivotalmovement about spaced centers for free swinging movement to permitadvancement of the wooden pieces thereunder but angularly positioned toresist displacement of the wooden pieces backwards while in the area tobe engaged by the cutting knives. An additional hold-down dog 21 issupported on spaced arms 22 mounted on the shaft 23 forming the axisabout which the spool or disc plates are rotated and the hold-down dog21 is angularly arranged so that its inner edge 24 is continually a verysmall fixed distance from the locus of the periphery of the cutterheads.

The cutting device comprises a pair of laterally spaced and verticallydisposed disc plates 25 and 26 fixed on opposite ends of shaft 23 forconjoint rotational movement as a spool. The shaft is supported at itsend portions extending beyond the disc plates in suitable journal boxes(not shown) held in fixed position on standards. Rotational movement isimparted to the shaft 23 and conjointly to the disc plates mountedthereon by a driving motor 27 connected to a sprocket 28 on the shaft bymeans of a chain or belt 29. It will be understood that other means forrotating the shaft and disc plates may One or more openings 30 areprovided in the peripheral end portions of each disc plate in alignmentwith each other for purposes of mounting a cutter head, indicated by theletter A, therebetween. For purposes of balance and to secure greaterproduction, it is preferred to employ more than one cutter head and toequidistantly space the cutter heads about the periphery of the diskplates, such for example as the six cutter heads mounted on the diskplate, as illustrated in Figure 1.

As illustrated in Figure 2, each cutter head A includes a shaft 31xtending laterally across the space between the disk plates through theopenings and into bearings 32 and 33 secured to the side walls of theplates in registry with the openings. The shafts may be actuated intheir respective bearings for rotational movement independent of thedisk plates by gearing fixed to the end of the shafts and to the mainshaft 23, or as shown, by individual motors 34 mounted on a portion ofthe same shaft extending beyond its bearings. It is desirable to providemeans for radial adjustment of the shafts as through the bearings toenable more perfect alignment of the shaft circumferentially about thedisk plates, as by means of radially extending slots either in the diskplate or bearing, and means such as bolts and nuts 35 for securing theelements in their adjusted position.

The cutter head which is mounted on the shaft for rotational movementtherewith between the disk plates comprises a cylindrical member 36formed of metal, such as steel, having a plurality of slots or gullets39 preferably arranged in equally spaced apart relation about theperiphery of the cylinder and extending angularly into the cylinder fromthe peripheral surfrace thereof, such as at a preferred angle of about30 to the tangent of the cylinder. In the preferred form, the slotsextend continuously across the cylinder for receiving an elongate cutterblade 40 in fixed relation within each slot. The blades are slotted foroperative engagement of the securing screws, and the blade can beadjusted outwardly for proper alignment or for increasing the protrusionof the cutting edge.

When the cutting blades 40 fixed in the cylinder 36 and extendingcontinuously across the cylinder are formed with scallops or of a seriesof short blades 49b in spaced apart relation and staggered with theblades 400 of adjacent sets of knives, the width of the blades and thespaced relation between the blades transversely of the cylinder willdetermine one dimension of the fibers cutthe width. Under suchcircumstances, however, the usable cutting area is reduced by one-halfand it is preferred, for more eiiicient use, to make use of cutterblades which provide a cutting surface extending continuously across thecylinder and to rely upon scoring knives 41 to engage the surface of thewooden pieces in advance to score the wood to depths slightly greaterthan the thicknesses to be cut by cutting knives which engage the woodin advance of the next scoring member. The lateral spacing of thescoring knives then determines the width of the wafers severed from theblock.

As illustrated in Figure 3, the scoring blades 41 are mounted in a bar42 fixed, as by screws 43, in notches provided in the periphery of thedisk plates 25 and 26 to extend between the disk plates. Slots 44 areprovided in laterally spaced apart relation through the bar forinsertion of the scoring knives 41 to extend the cutting edges at anacute angle of about 20-50 and preferably about 30 to a predetermineddistance beyond the periphery of the disk plates and by a distance whichis at least equal to and preferably greater than the thicknessof thewafers to be cut. The scoring members are fixed in adjusted position bymeans such as a setscrew 4 5 operating through threaded openings 46inthe bar 42 for engagement with the shank of the scoring elements. It ispreferred to make use of a bar supporting a plurality of spaced apartscoring elements for every pair of rotary cutting heads, but more orless may be used with the corresponding depth of score.

In operation, the disc plates are adapted to be rotated by the motor 27in a counterclockwise direction in Figure 1, that is in a direction tobring the cutter heads down onto the wooden pieces from above and thecutting cylinders mounting the cutting blades are also rotatedindependently of the disc plates in a counterclockwise direction so thatthe movement of the blades relative the piece of wood will constitutethe sum of the peripheral speeds of the disc plate and the cuttingcylinder. The revolving cutters sever elements from the face of thewooden pieces advancedto their locus. The thickness of the elements cutmay, if desired, be varied by adjusting the rate of feed as determinedby the linear speed of the feed chain.

The elements severed by the cutting knives of the cutter heads aredischarged tangentially downward into a suitable receiver or upon asuitable conveyor (not shown) positioned therebeneath. In thealternative, other means for. feeding wooden pieces tothe apparatus mayadvantageously be employed particularly when the pieces of wood beingfed are of small dimension and modification in an apparatus of the typedescribed is diagrammatically shown in Figure 5.

In this modification, the disc plate carrying cutters as described inFigure 1 is enclosed about its periphery to form a drum 50 whichfunctions as the under support for a hopper into which pieces of wood 52are fed. In this modification, the cutter head of the type described isentered sideways in a substantially cylindrical recess 53 in the drumand it is assembled and secured by bolts to the disc plates 25 and 26,as in Figure 1, but in such position that the cutting blades extendbeyond the surface of the drum by an amount equal to the thicknessdesired in the elements. When an element is cut from a piece of wood, itwill be contained in the gullets 39 in advance of each knife and sweptaround the cylindrical recess 36 for discharge by centrifugal action. Ithas been found desirable, in a construction of the type described, toincline the front and back walls 55 and 56 of the hopper in theforwardly direction, as shown. By so doing, the cutting force of theknives operates to wedge the wooden pieces in the front of the hopper sothat the surface of the cylinder not only functions to hold the woodenelements stationary but the slope reacts in assistance to gravitationalforce in feeding the wooden pieces into engagement with the cuttingknives for Wafering. In the alternative, auxiliary pressure means suchas pressure feet or caterpillar chains, commonly used in apparatus forwet grinding of wood in the manufacture of pulp fibers, may be used toadvance the pieces of wood positively and uniformly into cuttingrelation with the knives on the cutter cylinder.

For the manufacture of fibrous structures of low density, such asacoustical tile and the like, it is desirable to cut the fibrouselements with knives having their edges held across and moved parallelto the grain of the wood. For denser structures, such as are describedin the copending application Ser. No. 94,812, filed on May 23, 1949, nowPatent No. 2,689,092, or in the copending application Ser. No. 192,284,filed on October 26, 1950, it is desirable to cut the elements with thecutting blades parallel to and across the grain of the wood.

By way of illustration of conditions for operation, it isdesirable torotate the disk plates at a peripheral speed which is preferably atleast one-fifth the peripheral speed of the cutter heads. The latterpreferably should have a peripheral speedin excess of 3,000 feet per 3above, it would be preferred to rotate the disk plates at least 920 feetper minute and preferably much higher speeds.

Referring to Figure 4, AT represents the basic length of the element andCD its thickness. Since AD DT equals CD DE or approximately CD X CE,when CD is 0.025 inch and CE is 10 inches, CD CE equals A square inchand AD therefore equals /1 inch. Thus, under these conditions, the basiclength of the element AT will be 1 inch. When it is desired to increasethe length, as to 1 /2 inches, then while the cutting knife is engagedin the wood from T to A, it will be necessary to move the spool carryingthe head through a distance GT plus AH, that is, through the extra /2inch desired.

Under these illustrative conditions, the peripheral speed of the diskplates would be adjusted to one-half that of the cutter heads or 2300feet per minute since the center of the cutter head I will have to move/2 inch while it rotates from T to A,- which is approximately 1 inch,the basic length of a 0.025 inch element made with a, 10 inch diameterhead. It will be apparent that if the cutter head moved very slowlyforward in comparison to its peripheral speed, the shape of the elementcut would be somewhat triangular as represented by the letters CAH inFigure 4 and the length slightly greater than AC, or /2 inch, for thecondition cited. It is preferred that the knives be spaced apart tocorrespond to the maximum length desired for the element.

It will be apparent from the description that there is provided animproved mechanism for severing wafers from blocks of wood such as woodwaste and the like to produce elements which may be varied as desired inthickness, in length, in the tapers of the edges and in the direction ofcut in accordance with the uses to be made thereof, whether in themanufacture of boards molded under heat and pressure or acoustical tileof lower density or the like. The apparatus described embodies means forpositively feeding and maintaining the pieces of Wood to be waferized inposition for engagement with the cutting elements so as to produce amore uniform and more desirable wafer for use in the manufacture ofstructures having better control as to strength, appearance anduniformity of fibers contained therein.

As previously described, the thickness of the wafers cut will dependchiefly on the rate of feed of the wooden blocks into the area forengagement with the cutting blades. The length of the fibers, aspreviously described, also depends upon relative movement between thecutting blades in the cutter head and the speed of rotation thereof. Theother dimension remains positive and is independent of the rate of feedor speeds of rotation since it depends on the spaced relation betweenthe scoring elements across the space between the disk plates or thewidth of the scallops or staggered knives forming the cutting elements.

As used herein and in the claims, the phrase cut sub stantially parallelto the grain of the wood is meant to include cutting by knives havingtheir edges held across and moved parallel to the grain of the wood orelse held parallel to and moved across the grain of the wood.

It will be understood that other means may be employed for advancing thewooden 'elementsin feeding relation with the cutter heads and that otherchanges may be made in the details of construction, arrangement andoperation, particularly with respect to the mounting and to thearrangement of the cutter heads and scoring elements in the periphery ofa rotating cylinder for operative engagement with pieces of wood to beseparated into wafers of predetermined dimension and curvature, withoutdeparting from the spirit of the invention, especially as defined in thefollowing claims.

What is claimed is: r

1. Apparatus for reducing blocks of wood into fibrous elements taperedat both ends and cut substantially parallel to the grain of the woodcomprising a supporting frame mounted for rotational movement aboutanaxis, a plurality of spaced cutting cylinders mounted for independentrotational movement in said frame about a parallel axis and positionedin equally spaced relation from the frame axis, a plurality of cuttingblades extending crosswise from the periphery of the cylinder, drivingmeans for rotating the frame and for rotating the cutting cylindersindependently of the frame but in the same direction thereof, means forfeeding blocks of wood with the grain of the wood parallel to the axisin the direction toward the frame into engagement with the cuttingblades for severing fibrous elements from the blocks, and scoringmembers positioned on the frame intermediate the cutting cylinders andspaced from the axis of the frame to extend slightly beyond the bladeson the cutting cylinders.

2. Apparatus as claimed in claim 1 in which the scoring members arespaced one from another crosswise on the frame and in which thelaterally spaced relation corresponds to the width of the fibrouselements to be cut.

3. Apparatus as claimed in claim 1 in whichthe scoring elements areinclined at an angle of between 2050 from the radial.

4. Apparatus for reducing the side face of a block of wood along itsentire length into fibrous elements cut parallel to the grain of thewood comprising a framework mounted for rotational movement about itsaxis, a plurality of elongate cutting cylinders .mounted incircumferentially spaced apart relation in outer portions of theframework to extend across the length thereof and for rotationalmovement independent of the framework about separate axes parallel tothe axis of the framework, cutting blades extending outwardly from theperiphery of the cutting cylinders parallel to their axes for a lengthcorresponding at least to the length of the block of Wood, means foractuating the framework for rotational movement about its axis to carrythe cutting cylinders therewith, means for actuating the cuttingcylinders for rotational movement at high speed about their respectiveaxes independent of the rotational movement of the framework, andfeeding means for advancing the block of wood towards the periphery ofthe rotating cylinders with its face substantially parallel to the axisof rotation .of the cutting cylinders and the framework.

5. Apparatus for reducing the side face of a block of wood along itsentire length into fibrous elements cut parallel to the grain of thewood comprising a cylindrical frame mounted for rotational movementabout its axis and dimensioned to have a length greater than the lengthoffie block of wood, a plurality of elongate cutting cylinders mountedin circumferentially spaced apart relation in the peripheral portion ofthe frame for rotational movement independent of the frame about axesparallel to the axis of the frame, cutting blades extending .outwardlyperipherally from the cutting cylinders parallel to their axes andhaving a length corresponding at least to the length of the block ofwood, means for actuating the cylindrical frame for rotational movementabout ,its axis, means for actuating the cylinders for independentrotational movement about their respective axes, and

feeding means for advancing the block of wood towards the periphery ofthe rotating cylinders with its face substantially parallel to the axisof rotation of the cutting cylinders and the framework.

6. Apparatus for reducing the side face of a block of wood along itsentire length into fibrous elements cut parallel to the grain of thewood comprising a framework mounted for rotational movement about itsaxis, a plurality of elongatecutting cylinders mounted incircumferentially spaced apart relation in the outer periphery S of theframework and for rotational movement independent of the framework aboutseparate axes parallel to the axis of the framework, cutting bladesextending outwardly radially from the periphery of the cutting cylindersand from the framework dimensioned to have a length corresponding atleast to the length of the block of wood, means for actuating theframework for rotational movement about its axis, means for actuatingthe cutting cylinders for rotational movement at high speed about theirrespective axes independent of the rotational movement of the framework,and feeding means for advancing the block of wood towards the peripheryof the rotating cylinders with its face substantially parallel to theaxis of rotation of the cutting cylinders and the framework.

7. Apparatus for reducing the side face of a block of wood along itsentire length into fibrous elements cut parallel to the grain of thewood, comprising a plurality of rapidly rotating cutting cylinders, eachbearing staggered cutting edges on its periphery and parallel to itsaxis, said edges being as long as the width of the fibrous elements andspaced along the cylinder for at least the length of the block of wood,a framework rotating rapidly in the same direction as said cylinders andbearing a plurality of said cylinders on its periphery, and

a feeding means for advancing said block towards the rotating cylinderswith its face substantially parallel to the axes of rotation of thecutting cylinders and the framework.

8. Apparatus for reducing the side face of a block of wood along itsentire length into fibrous elements cut parallel to the grain of theWood, comprising a framework mounted for rotational movement about itsaxis, a plurality of elongate cutting cylinders mounted in cir-'cumferentially spaced apart relation in the outer periphery of theframework and for rotational movement independent of the framework aboutseparate axes parallel to the axis of the framework, cutting elementsextending outwardly from the periphery of the cylinders and from theperiphery of the framework and having staggered cutting edges, each ofwhich is dimensioned to have a length corresponding to the width of thefibrous elements and spaced along the cutting cylinder for at least thelength of the block of wood, means for actuating the framework forrotational movement about its axis, means for actuating the cuttingcylinders for rotational movement at high speed about their respectiveaxes independent of the rotational movement of the framework, andfeeding means for advancing the block of wood towards the periphery ofthe rotating cylinders with its face substantially parallel to the axisof rotation of the cutting cylinders and the framework.

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